You can implement SBG without any fundamental changes.

There’s a problem with the term “Standards-Based Grading:” it’s too overloaded. The word “standard” means ten different things, and so newcomers to SBG don’t know what it is from the name (e.g. “I have standards too, you prick.”) Even within the community of SBG believers, there’s confusion: do you have to allow remediation under SBG? Is it still SBG if I have deadlines and late penalties?

But changing to standards-based grading can be very simple. Just group grades by knowledge. Don’t say, “you have 95% in projects, 80% on tests, and 85% in homework.” Instead, report that “you’ve earned 95% in graphing lines, 80% in graphing general functions, 85% in composing functions.” It doesn’t have to be philosophical – this is just more information for your students.